EP0538684B1 - Burner with reduced emission of pollutants - Google Patents
Burner with reduced emission of pollutants Download PDFInfo
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- EP0538684B1 EP0538684B1 EP92117234A EP92117234A EP0538684B1 EP 0538684 B1 EP0538684 B1 EP 0538684B1 EP 92117234 A EP92117234 A EP 92117234A EP 92117234 A EP92117234 A EP 92117234A EP 0538684 B1 EP0538684 B1 EP 0538684B1
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- Prior art keywords
- fuel
- burner
- oxidizing gas
- combustion
- outlet openings
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
- F23D14/32—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid using a mixture of gaseous fuel and pure oxygen or oxygen-enriched air
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
- F23D14/20—Non-premix gas burners, i.e. in which gaseous fuel is mixed with combustion air on arrival at the combustion zone
- F23D14/22—Non-premix gas burners, i.e. in which gaseous fuel is mixed with combustion air on arrival at the combustion zone with separate air and gas feed ducts, e.g. with ducts running parallel or crossing each other
Definitions
- the invention relates to a burner for low-pollutant combustion of a fuel with an oxidizing gas with at least one supply channel for the fuel and at least one supply channel for the oxidizing gas.
- Such burners are e.g. known from EP-A-0 012 308.
- Nitrogen oxides arise during the combustion process essentially from the molecular nitrogen (“thermal NO x ”) present in the combustion air or in the fuel (eg natural gas) and from the nitrogen (“fuel NO x ”) bound in the fuel (eg coal, heating oil).
- Thermal nitrogen oxide is generated in the area of the flame root or in hot flame zones at temperatures above 1300 ° C from dissociated oxygen and nitrogen molecules.
- the thermal NO x formation depends on the concentration of the molecular nitrogen and dissociated oxygen and strongly dependent on the temperature.
- the oxygen concentration of the combustion air or the oxidizing gas is primarily decisive for the fuel NO x formation.
- the air ratio ⁇ is a major influencing factor in NO x formation.
- Oxygen-enriched air or pure oxygen are therefore used as the oxidizing gas in order to minimize the supply of nitrogen.
- this results in higher flame temperatures and a higher oxygen partial pressure.
- To reduce the oxygen supply use is made of the return of burned exhaust gases to the combustion air or the oxidizing gas, which on the one hand reduces the oxygen content by dilution, and on the other hand lowers the combustion temperature due to the exhaust gas ballast, which extracts heat from the flame.
- the supply of cooled exhaust gases to the area of the flamen root is efficient.
- Staged combustion is also suitable for the same purpose (Gas pulp International, 39 (1990), No. 6, June).
- Stage combustion burners point downstream, i.e. in the direction of the flame, drawn supply ducts for the combustion air or the oxidizing gas, which allow access to only a small amount of oxygen through primary air openings in the lower part near the burner, and in the upper part through secondary and tertiary air openings to allow access to the corresponding amount of near-stoichiometric combustion.
- the flame temperature thus remains far below that which occurs in single-stage combustion.
- This step combustion implemented with so-called “secondary air obstacles” in the combustion air supply duct, has the disadvantages that these obstacles, which surround the burner in the form of a jacket, are exposed to severe heat, since they are located downstream of the fuel gas opening, and that the mold the casing has a strong influence on the CO emission, which must be determined before the burner is used and which makes many embodiments unusable due to excessive CO emissions.
- This measure according to the invention makes optimal use of all possibilities for reducing pollutants.
- the elongated opening cross-sections have a larger circumference than the previous circular ones with the same cross-sectional area and therefore make it possible to return a larger amount of furnace exhaust gases into the oxidizing gas jet.
- This inert exhaust gas ballast sucked into the oxidation gas jets lowers the flame temperature and the oxygen partial pressure more than before and thus effectively prevents NO x formation.
- Another advantage of the burner according to the invention is that the diameter of the burner head can be kept small in spite of the enlarged suction surface for furnace exhaust gases.
- the oxidizing gas openings had to be as far away as possible from the fuel gas opening, which considerably increased the dimensions of the burner head.
- narrow supply channels for oxidizing gas were then necessary in the immediate vicinity of the fuel gas opening in order to keep the flame stable at the burner mouth and to prevent the flame from being torn off.
- both a large amount of furnace exhaust gases can be sucked back into the flame and the flame can be held stably at the burner mouth without the diameter of the burner head having to be significantly increased.
- the tips of the wedge-shaped outlet openings for the oxidizing gas point to the axis of a feed channel for the fuel, the fuel escaping there is mixed with only a small amount of oxidizing gas, so that the flame burns under-stoichiometrically and at the same time is held stably at the burner mouth.
- the radially outward widening wedge-shaped cross section of the oxidizing gas jets then causes the combustible gas to be burned with an amount of oxidizing gas corresponding to the near-stoichiometric combustion only with increasing distance from the burner mouth.
- the area of the oxidizing gas jets required for sucking in furnace exhaust gases increases in the radial direction towards the outside.
- the substoichiometric combustion in the area of the flame root with the combustion that completes downstream contributes significantly to the reduction of the nitrogen oxide values.
- the inner distance between the outlet opening of a feed channel for the fuel and the outlet openings of the feed channels for the oxidizing gas is at least 20% of the diameter of the outlet opening of the feed channel for the fuel. It is usually sufficient if this distance is less than 50% of the diameter of the outlet opening for the fuel.
- the flame can then be held steadily on the burner mouth, on the other hand there is a sufficiently large suction surface for furnace exhaust gases without over-dimensioning the burner mouth.
- An exemplary embodiment is intended to explain the burner according to the invention in more detail and to describe its advantages.
- the drawing schematically shows the top view of the burner mouth 4 of a burner according to the invention with a feed channel 2 arranged in the middle of the burner mouth 4 for the fuel natural gas and about the axis 3 of this feed channel 2 concentrically arranged feed channels for the oxidizing gas, as pure oxygen is used.
- the outlet opening of the feed channel 2 for the fuel is circular in this case, whereas the outlet openings 1 of the feed channels for the oxidizing gas are wedge-shaped according to the invention.
- the longitudinal axes of these wedge-shaped outlet openings 1 are aligned in the radial direction with the axis 3 of the supply channel 2 for the fuel.
- the alignment of the wedge-shaped outlet openings 1 for the oxidizing gas allows the inflow of an amount of oxygen decreasing from the outside inwards in the radial direction, so that in the vicinity of the outlet openings of the supply duct 2 for the natural gas, the latter is burned sub-stoichiometrically, at the same time the flame stably at the burner mouth 4 can be held.
- the increasing amount of oxygen flowing out of the wedge-shaped outlet openings 1 in the radial direction only mixes further downstream with the incompletely burned natural gas and finally burns it completely. As a result, stage combustion that is very effective for NO x reduction is realized.
- Opening angle and cross-sectional area of the wedge-shaped outlet openings 1 for the oxygen and the number of feed channels for the oxidizing gas are dimensioned such that the flame in the end region is close to stoichiometric and burns substoichiometrically at the flame root.
- the number of feed channels for the oxygen is six, and the cross-sectional area of each outlet opening 1 of these feed channels is approximately one third of the cross-sectional area of the outlet opening for the natural gas.
- the opening angle of the wedge-shaped outlet openings 1 is approximately 6 °.
- the inner distance between the outlet openings 1 for the oxygen and the outlet opening of the inlet channel 2 for the natural gas is 25% of the diameter of the outlet opening of this inlet channel 2.
- the geometric shape of the outlet openings 1 according to the invention for the oxidation for the oxygen jets allows a large amount of furnace exhaust gases to be drawn in in the area of the flame root. As a result, the flame is cooled and the oxygen partial pressure is reduced, likewise two mechanisms that prevent NO x formation.
- Exhaust gas measurements during operation of the burner according to the invention with a firing capacity of 0.8 MW result in approximately 160 mg NO x / Nm 3 exhaust gas and approximately 120 mg CO at an oven chamber temperature of approximately 1350 ° C. and an oxygen content in the exhaust gas of 4%. This means that the relevant TA-Luft limit values are clearly undercut.
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Abstract
Description
Die Erfindung betrifft einen Brenner zur schadstoffarmen Verbrennung eines Brennstoffes mit einem Oxidationsgas mit mindestens einem Zuleitungskanal für den Brennstoff und mindestens einem Zuleitungskanal für das Oxidationsgas. Solche Brenner sind z.B. aus der EP-A-0 012 308 bekannt.The invention relates to a burner for low-pollutant combustion of a fuel with an oxidizing gas with at least one supply channel for the fuel and at least one supply channel for the oxidizing gas. Such burners are e.g. known from EP-A-0 012 308.
Brenner, die eine reduzierte Emission an Schadstoffen, insbesondere an den umweltschädlichen Stickoxiden, aufweisen sollen, müssen einer Verbrennungstechnik angepaßt sein, die die Entstehung solcher Schadstoffe herabzusetzen sucht.Burners which are said to have a reduced emission of pollutants, in particular of the environmentally harmful nitrogen oxides, must be adapted to a combustion technology which attempts to reduce the formation of such pollutants.
Stickoxide entstehen beim Verbrennungsvorgang im wesentlichen aus dem in der Verbrennungsluft oder im Brennstoff (z.B. Erdgas) vorhandenen molekularen Stickstoff ("thermisches NOx") und aus dem im Brennstoff (z.B. Kohle, Heizöl) gebundenen Stickstoff ("Brennstoff-NOx"). Thermisches Stickoxid entsteht im Bereich der Flammenwurzel oder in heißen Flammenzonen bei Temperaturen oberhalb 1300 °C aus dissoziierten Sauerstoff- und Stickstoff- Molekülen. Die thermische NOx-Bildung ist von der Konzentration des molekularen Stickstoffs sowie des dissoziierten Sauerstoffs und stark von der Temperatur abhängig. Für die Brennstoff-NOx-Bildung ist in erster Linie die Sauerstoffkonzentration der Verbrennungsluft bzw. des Oxidationsgases maßgebend. Somit ist in beiden Fällen die Luftzahl λ eine Haupteinflußgröße bei der NOx-Bildung.Nitrogen oxides arise during the combustion process essentially from the molecular nitrogen ("thermal NO x ") present in the combustion air or in the fuel (eg natural gas) and from the nitrogen ("fuel NO x ") bound in the fuel (eg coal, heating oil). Thermal nitrogen oxide is generated in the area of the flame root or in hot flame zones at temperatures above 1300 ° C from dissociated oxygen and nitrogen molecules. The thermal NO x formation depends on the concentration of the molecular nitrogen and dissociated oxygen and strongly dependent on the temperature. The oxygen concentration of the combustion air or the oxidizing gas is primarily decisive for the fuel NO x formation. Thus, in both cases, the air ratio λ is a major influencing factor in NO x formation.
Untersuchungen zeigen, daß die Konzentration der Stickoxide mit der Ofenraumtemperatur steigt sowie exponentiell mit der Verbrennungslufttemperatur, ein Maximum im nahstöchiometrischen Verbrenungsbereich (Luftzahl λ ungefähr 1,1) besitzt und zum unter- und überstöchiometrischen Bereich (λ = 0,6 bzw. λ = 1,6) hin stark absinkt. Die Konzentration der Stickoxide kann durch Rezirkulation der Abgase gesenkt werden, wobei die NOx-Minderung exponentiell mit der Menge des zurückgeführten Abgasstroms zusammenhängt (Gas Wärme International 38 (1989), Heft 10, Dezember).Studies show that the concentration of nitrogen oxides increases with the furnace chamber temperature and exponentially with the combustion air temperature, has a maximum in the near-stoichiometric combustion range (air ratio λ approximately 1.1) and to the sub-stoichiometric range (λ = 0.6 or λ = 1 , 6) drops sharply. The concentration of nitrogen oxides can be reduced by recirculating the exhaust gases, the NO x reduction being exponentially related to the amount of the exhaust gas stream returned (Gas Wärme International 38 (1989), issue 10, December).
In der Verbrennungstechnik werden zur Reduktion der Stickoxide eine Erniedrigung der Sauerstoff- und Stickstoff-Partialdrücke und der Verbrennungstemperatur angestrebt.In combustion technology, to reduce nitrogen oxides, the oxygen and nitrogen partial pressures and the combustion temperature are reduced.
Als Oxidationsgas werden deshalb sauerstoffangereicherte Luft oder reiner Sauerstoff verwendet, um das Angebot an Stickstoff zu minimieren. Dies hat jedoch höhere Flammentemperaturen und einen höheren Sauerstoff-Partialdruck zur Folge. Zur Senkung des Sauerstoffangebots macht man von der Rückführung ausgebrannter Abgase in die Verbrennungsluft bzw. das Oxidationsgas Gebrauch, wodurch einerseits der Sauerstoffgehalt durch Verdünnung reduziert wird, andererseits die Verbrennungstemperatur aufgrund des Abgasballastes abgesenkt wird, der der Flamme Wärme entzieht. Effizient ist hierbei die Zufuhr abgekühlter Abgase in den Bereich der Flamenwurzel.Oxygen-enriched air or pure oxygen are therefore used as the oxidizing gas in order to minimize the supply of nitrogen. However, this results in higher flame temperatures and a higher oxygen partial pressure. To reduce the oxygen supply, use is made of the return of burned exhaust gases to the combustion air or the oxidizing gas, which on the one hand reduces the oxygen content by dilution, and on the other hand lowers the combustion temperature due to the exhaust gas ballast, which extracts heat from the flame. The supply of cooled exhaust gases to the area of the flamen root is efficient.
Geeignet zum gleichen Zweck ist auch die Stufenverbrennung (Gas Wärme International, 39 (1990), Heft 6, Juni). Brenner zur Stufenverbrennung weisen stromabwärts, d.h. in Flammenrichtung, gezogene Zuleitungskanäle für die Verbrennungsluft bzw. das Oxidationsgas auf, die durch Primärluftöffnungen im unteren brennernahen Teil den Zutritt einer nur geringen Sauerstoffmenge, im oberen Teil durch Sekundär- und Tertiärluftöffnungen den Zutritt der nahstöchiometrischen Verbrennung entsprechenden Sauerstoffmenge erlauben. Die Flammentemperatur bleibt dadurch weit unterhalb der bei einstufiger Verbrennung auftretenden.Staged combustion is also suitable for the same purpose (Gas Wärme International, 39 (1990), No. 6, June). Stage combustion burners point downstream, i.e. in the direction of the flame, drawn supply ducts for the combustion air or the oxidizing gas, which allow access to only a small amount of oxygen through primary air openings in the lower part near the burner, and in the upper part through secondary and tertiary air openings to allow access to the corresponding amount of near-stoichiometric combustion. The flame temperature thus remains far below that which occurs in single-stage combustion.
Diese mit sogenannten "Sekundärluft-Hindernissen" in den Zufuhrkanal für die Verbrennungsluft verwirklichte Stufenverbrennung hat die Nachteile, daß diese Hindernisse, die den Brenner in Form einer Ummantelung umgeben, starker Hitzeeinwirkung ausgesetzt sind, da sie stromabwärts von der Brenngasöffnung liegen, und daß die Form der Ummantelung starken Einfluß auf die CO-Emission hat, die jeweils vor Einsatz des Brenners bestimmt werden muß und viele Ausführungsformen wegen zu hohen CO-Emissionen unbrauchbar macht.This step combustion, implemented with so-called "secondary air obstacles" in the combustion air supply duct, has the disadvantages that these obstacles, which surround the burner in the form of a jacket, are exposed to severe heat, since they are located downstream of the fuel gas opening, and that the mold the casing has a strong influence on the CO emission, which must be determined before the burner is used and which makes many embodiments unusable due to excessive CO emissions.
Aufgabe vorliegender Erfindung ist es folglich, einen verbesserten Brenner zu entwickeln, der die geschilderten Möglichkeiten zur Reduktion von Schadstoffen optimal auszunutzen gestattet und die genannten Nachteile bekannter Brennerausführungen vermeidet.It is therefore an object of the present invention to develop an improved burner which allows the described possibilities for reducing pollutants to be used optimally and avoids the disadvantages of known burner designs.
Diese Aufgabe wird erfindungsgemäß durch die Merkmale des Patentanspruchs 1 gelöst.This object is achieved by the features of claim 1.
Durch diese erfindungsgemäße Maßnahme werden sämtliche Möglichkeiten zur Schadstoffverringerung optimal genutzt. Die länglichen Öffnungsquerschnitte besitzen im Vergleich zu den bisherigen kreisförmigen einen größeren Umfang bei gleicher Querschnittsfläche und ermöglichen daher, eine größere Menge von Ofenabgasen in den Oxidationsgasstrahl zurückzuführen. Dieser in die Oxidationsgasstrahlen gesaugte inerte Abgasballast senkt die Flammentemperatur und den Sauerstoff-partialdruck stärker als bisher und verhindert damit effektiv eine NOx-Bildung.This measure according to the invention makes optimal use of all possibilities for reducing pollutants. The elongated opening cross-sections have a larger circumference than the previous circular ones with the same cross-sectional area and therefore make it possible to return a larger amount of furnace exhaust gases into the oxidizing gas jet. This inert exhaust gas ballast sucked into the oxidation gas jets lowers the flame temperature and the oxygen partial pressure more than before and thus effectively prevents NO x formation.
Ein weiterer Vorteil des erfindungsgemäßen Brenners besteht darin, daß der Durchmesser des Brennerkopfes trotz der vergrößerten Ansaugfläche für Ofenabgase kleingehalten werden kann. Bisher mußten nämlich, um eine große Menge an Ofenabgasen zurückzusaugen, die Oxidationsgasöffnungen möglichst weit von der Brenngasöffnung entfernt sein, wodurch die Dimensionen des Brennerkopfes beträchtlich zunahmen. Zusätzlich waren dann noch schmale Zuleitungskanäle für Oxidationsgas in unmittelbarer Nähe der Brenngasöffnung notwendig, um die Flamme stabil am Brennermund zu halten und ein Abreißen der Flamme zu verhindern. Diese aufwendigen und umständlichen Maßnahmen werden beim erfindungsgemäßen Brenner überflüssig. Durch die erfindungsgemäße Geometrie der Querschnittsöffnungen für das Oxidationsgas kann sowohl eine große Menge Ofenabgase in die Flamme zurückgesaugt werden als auch die Flamme stabil am Brennermund gehalten werden, ohne daß der Durchmesser des Brennerkopfes nennenswert vergrößert werden muß.Another advantage of the burner according to the invention is that the diameter of the burner head can be kept small in spite of the enlarged suction surface for furnace exhaust gases. Until now, in order to suck back a large amount of furnace exhaust gases, the oxidizing gas openings had to be as far away as possible from the fuel gas opening, which considerably increased the dimensions of the burner head. In addition, narrow supply channels for oxidizing gas were then necessary in the immediate vicinity of the fuel gas opening in order to keep the flame stable at the burner mouth and to prevent the flame from being torn off. These complex and cumbersome measures are unnecessary in the burner according to the invention. Due to the geometry of the cross-sectional openings for the oxidizing gas according to the invention, both a large amount of furnace exhaust gases can be sucked back into the flame and the flame can be held stably at the burner mouth without the diameter of the burner head having to be significantly increased.
Als vorteilhaft erweist es sich, wenn die Austrittsöffnungen eines jeden Zuleitungskanals für das Oxidationsgas in ihrem Querschnitt keilförmig ausgebildet sind. Damit läßt sich eine Stufenverbrennung realisieren.It proves to be advantageous if the cross-section of the outlet openings of each feed channel for the oxidizing gas is wedge-shaped. Step combustion can thus be implemented.
Zeigen die Spitzen der keilförmigen Austrittsöffnungen für das Oxidationsgas auf die Achse eines Zuleitungskanals für den Brennstoff, wird der dort austretende Brennstoff mit einer nur geringen Menge an Oxidationsgas gemischt, so daß die Flamme dort unterstöchiometrisch brennt und gleichzeitig stabil am Brennermund gehalten wird. Der sich radial nach außen verbreiternde keilförmige Querschnitt der Oxidationsgasstrahlen bewirkt dann, daß erst mit wachsendem Abstand vom Brennermund das Brenngas mit einer der nahstöchiometrischen Verbrennung entsprechenden Oxidationsgasmenge verbrannt wird. Außerdem nimmt bei dieser Anordnung die zum Ansaugen von Ofenabgasen benötigte Fläche der Oxidationsgasstrahlen in radialer Richtung nach außen hin zu.If the tips of the wedge-shaped outlet openings for the oxidizing gas point to the axis of a feed channel for the fuel, the fuel escaping there is mixed with only a small amount of oxidizing gas, so that the flame burns under-stoichiometrically and at the same time is held stably at the burner mouth. The radially outward widening wedge-shaped cross section of the oxidizing gas jets then causes the combustible gas to be burned with an amount of oxidizing gas corresponding to the near-stoichiometric combustion only with increasing distance from the burner mouth. In addition, with this arrangement, the area of the oxidizing gas jets required for sucking in furnace exhaust gases increases in the radial direction towards the outside.
Die unterstöchiometrische Verbrennung im Bereich der Flammenwurzel mit der sich flammabwärts vervollständigenden Verbrennung trägt erheblich zur Senkung der Stickoxidwerte bei.The substoichiometric combustion in the area of the flame root with the combustion that completes downstream contributes significantly to the reduction of the nitrogen oxide values.
In diesem Zusammenhang erweist es sich als vorteilhaft, wenn der innere Abstand zwischen der Austrittsöffnung eines Zuleitungskanals für den Brennstoff und den Austrittsöffnungen der Zuleitungskanäle für das Oxidationsgas mindestens 20 % des Durchmessers der Austrittsöffnung des Zuleitungskanals für den Brennstoff beträgt. Meist ist es schon ausreichend, wenn dieser Abstand weniger als 50 % des Durchmessers der Austrittsöffnung für den Brennstoff beträgt. Einerseits kann die Flamme dann stabil am Brennermund gehalten werden, andererseits entsteht eine genügend große Ansaugfläche für Ofenabgase, ohne den Brennermund überzudimensionieren.In this context, it proves to be advantageous if the inner distance between the outlet opening of a feed channel for the fuel and the outlet openings of the feed channels for the oxidizing gas is at least 20% of the diameter of the outlet opening of the feed channel for the fuel. It is usually sufficient if this distance is less than 50% of the diameter of the outlet opening for the fuel. On the one hand, the flame can then be held steadily on the burner mouth, on the other hand there is a sufficiently large suction surface for furnace exhaust gases without over-dimensioning the burner mouth.
Im folgenden soll ein Ausführungsbeispiel den erfindungsgemäßen Brenner näher erläutern und seine Vorteile beschreiben.An exemplary embodiment is intended to explain the burner according to the invention in more detail and to describe its advantages.
Die Zeichnung zeigt schematisch die Aufsicht auf den Brennermund 4 eines erfindungsgemäßen Brenners mit einem in der Mitte des Brennermundes 4 angeordneten Zuleitungskanal 2 für den Brennstoff Erdgas und um die Achse 3 dieses Zuleitungskanals 2 konzentrisch angeordneten Zuleitungskanälen für das Oxidationsgas, als welches reiner Sauerstoff verwendet wird. Die Austrittsöffnung des Zuleitungskanals 2 für den Brennstoff ist in diesem Fall kreisförmig, wohingegen die Austrittsöffnungen 1 der Zuleitungskanäle für das Oxidationsgas erfindungsgemäß keilförmig ausgebildet sind. Die Längsachsen dieser keilförmigen Austrittsöffnungen 1 sind in radialer Richtung auf die Achse 3 des Zuleitungskanals 2 für den Brennstoff ausgerichtet.The drawing schematically shows the top view of the burner mouth 4 of a burner according to the invention with a
Die Ausrichtung der keilförmigen Austrittsöffnungen 1 für das Oxidationsgas erlaubt den Zustrom einer von außen nach innen in radialer Richtung abnehmenden Sauerstoffmenge, so daß in der Nähe der Austrittsöffnungen des Zuleitungskanals 2 für das Erdgas dieses dort unterstöchiometrisch verbrannt wird, wobei gleichzeitig die Flamme stabil am Brennermund 4 gehalten werden kann. Die in radialer Richtung zunehmende aus den keilförmigen Austrittsöffnungen 1 ausströmende Sauerstoffmenge mischt sich erst weiter stromabwärts mit dem unvollständig verbrannten Erdgas und verbrennt dieses schließlich vollständig. Dadurch wird eine für die NOx-Minderung sehr effektive Stufenverbrennung realisiert.The alignment of the wedge-shaped outlet openings 1 for the oxidizing gas allows the inflow of an amount of oxygen decreasing from the outside inwards in the radial direction, so that in the vicinity of the outlet openings of the
Öffnungswinkel und Querschnittsfläche der keilförmigen Austrittsöffnungen 1 für den Sauerstoff sowie die Anzahl der Zuleitungskanäle für das Oxidationsgas werden derart bemessen, daß die Flamme im Endbereich nahstöchiometrisch und an der Flammenwurzel unterstöchiometrisch brennt. In diesem Ausführungsbeispiel beträgt die Anzahl der Zuleitungskanäle für den Sauerstoff sechs, die Querschnittsfläche einer jeden Austrittsöffnung 1 dieser Zuleitungskanäle etwa ein Drittel der Querschnittsfläche der Austrittsöffnung für das Erdgas. Der Öffnungswinkel der keilförmigen Austrittsöffnungen 1 beträgt etwa 6°. Der innere Abstand zwischen den Austrittsöffnungen 1 für den Sauerstoff und der Austrittsöffnung des Zuleitungskanals 2 für das Erdgas beträgt 25 % des Durchmessers der Austrittsöffnung dieses Zuleitungskanals 2.Opening angle and cross-sectional area of the wedge-shaped outlet openings 1 for the oxygen and the number of feed channels for the oxidizing gas are dimensioned such that the flame in the end region is close to stoichiometric and burns substoichiometrically at the flame root. In this exemplary embodiment, the number of feed channels for the oxygen is six, and the cross-sectional area of each outlet opening 1 of these feed channels is approximately one third of the cross-sectional area of the outlet opening for the natural gas. The opening angle of the wedge-shaped outlet openings 1 is approximately 6 °. The inner distance between the outlet openings 1 for the oxygen and the outlet opening of the
Die erfindungsgemäße geometrische Form der Austrittsöffnungen 1 für die Oxidation für die Sauerstoffstrahlen erlaubt das Ansaugen einer großen Menge von Ofenabgasen im Bereich der Flammenwurzel. Dadurch wird eine Abkühlung der Flamme und eine Herabsetzung des Sauerstoffpartialdruckes erzielt, ebenfalls zwei die NOx-Bildung verhindernde Mechanismen.The geometric shape of the outlet openings 1 according to the invention for the oxidation for the oxygen jets allows a large amount of furnace exhaust gases to be drawn in in the area of the flame root. As a result, the flame is cooled and the oxygen partial pressure is reduced, likewise two mechanisms that prevent NO x formation.
Abgasmessungen beim Betrieb des erfindungsgemäßen Brenners bei einer Feuerungsleistung von 0.8 MW ergeben rund 160 mg NOx/Nm3 Abgas und etwa 120 mg CO bei einer Ofenraumtemperatur von etwa 1350 °C und einem Sauerstoffgehalt im Abgas von 4 %. Eine deutliche Unterschreitung der entsprechenden TA-Luft-Grenzwerte ist hiermit gegeben.Exhaust gas measurements during operation of the burner according to the invention with a firing capacity of 0.8 MW result in approximately 160 mg NO x / Nm 3 exhaust gas and approximately 120 mg CO at an oven chamber temperature of approximately 1350 ° C. and an oxygen content in the exhaust gas of 4%. This means that the relevant TA-Luft limit values are clearly undercut.
Claims (3)
- Burner for the low-pollution combustion of a fuel with an oxidizing gas, in which fuel and oxidizing gas flow out of the burner head in parallel directions from outlet openings through at least one supply duct in each case, characterized in that the outlet openings (1) of the supply ducts for the oxidizing gas are of elongated design in their cross section and are disposed concentrically around the axis (3) of each supply duct (2) for the fuel and their longitudinal axes are aligned with said axis or axes (3) in the radial direction.
- Burner according to Claim 1, characterized in that the outlet openings (1) of the supply ducts for the oxidizing gas are of wedge-shaped design in their cross section.
- Burner according to one of Claims 1 or 2, characterized in that the internal distance between the outlet opening of a supply duct (2) for the fuel and the outlet openings (1) of the supply ducts for the oxidizing gas is at least 20% of the diameter of the outlet opening of the supply duct (2) for the fuel.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4134979 | 1991-10-23 | ||
| DE4134979A DE4134979A1 (en) | 1991-10-23 | 1991-10-23 | BURNER WITH REDUCED POLLUTANT EMISSION |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| EP0538684A2 EP0538684A2 (en) | 1993-04-28 |
| EP0538684A3 EP0538684A3 (en) | 1993-07-14 |
| EP0538684B1 true EP0538684B1 (en) | 1997-01-29 |
Family
ID=6443257
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP92117234A Expired - Lifetime EP0538684B1 (en) | 1991-10-23 | 1992-10-08 | Burner with reduced emission of pollutants |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0538684B1 (en) |
| AT (1) | ATE148547T1 (en) |
| CZ (1) | CZ282672B6 (en) |
| DE (2) | DE4134979A1 (en) |
| ES (1) | ES2096693T3 (en) |
| SK (1) | SK319692A3 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102230631A (en) * | 2011-06-03 | 2011-11-02 | 王兴文 | Burner block of burner part of waste gas burning hot air furnace |
| GB2533293A (en) * | 2014-12-15 | 2016-06-22 | Edwards Ltd | Inlet assembly |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2853309C2 (en) * | 1978-12-09 | 1984-04-05 | Kernforschungsanlage Jülich GmbH, 5170 Jülich | Ceramic burner head for gaseous fuel |
| US4378205A (en) * | 1980-04-10 | 1983-03-29 | Union Carbide Corporation | Oxygen aspirator burner and process for firing a furnace |
| DE8905051U1 (en) * | 1988-04-28 | 1989-06-08 | Joh. Vaillant Gmbh U. Co, 5630 Remscheid | Burners, especially gas burners |
| US4969814A (en) * | 1989-05-08 | 1990-11-13 | Union Carbide Corporation | Multiple oxidant jet combustion method and apparatus |
-
1991
- 1991-10-23 DE DE4134979A patent/DE4134979A1/en not_active Withdrawn
-
1992
- 1992-10-08 EP EP92117234A patent/EP0538684B1/en not_active Expired - Lifetime
- 1992-10-08 DE DE59207985T patent/DE59207985D1/en not_active Expired - Fee Related
- 1992-10-08 ES ES92117234T patent/ES2096693T3/en not_active Expired - Lifetime
- 1992-10-08 AT AT92117234T patent/ATE148547T1/en not_active IP Right Cessation
- 1992-10-22 CZ CS923196A patent/CZ282672B6/en unknown
- 1992-10-22 SK SK3196-92A patent/SK319692A3/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| EP0538684A2 (en) | 1993-04-28 |
| ATE148547T1 (en) | 1997-02-15 |
| DE59207985D1 (en) | 1997-03-13 |
| SK319692A3 (en) | 1995-03-08 |
| DE4134979A1 (en) | 1993-04-29 |
| EP0538684A3 (en) | 1993-07-14 |
| ES2096693T3 (en) | 1997-03-16 |
| CZ282672B6 (en) | 1997-08-13 |
| CZ319692A3 (en) | 1993-06-16 |
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